CN1107399A

CN1107399A - Anti-oxidation method for inwall of steel pipe inlaid in casting

Info

Publication number: CN1107399A
Application number: CN 94110161
Authority: CN
Inventors: 张新一; 王德生
Original assignee: Benxi Iron & Steel Co
Current assignee: Benxi Iron & Steel Co
Priority date: 1994-03-28
Filing date: 1994-03-28
Publication date: 1995-08-30
Anticipated expiration: 2014-03-28
Also published as: CN1042805C

Abstract

In order to prevent the inwall of steel pipe embedded in casting from being oxidized, during pouring and cooling, nitrogen gas is introduced into the pipe and the pipe is then immediately sealed by means of a special cover, resulting in that oxidation does not occur and pickling is unnecessary.

Description

Anti-oxidation method for inwall of steel pipe inlaid in casting

A kind of anti-oxidation method for inwall of steel pipe that is set in the foundry goods belongs to the casting technique field.

When casting, need to be bumped into the steel pipe of cooling usefulness sometimes as required in foundry goods inside.When casting this class foundry goods, before cast, the seamless steel pipe of certain diameter is curved earlier the shape of requirement, be placed in the casting mold and fix, pour into a mould then.The baking that is subjected to high-temperature liquid metal owing to the steel pipe that is bumped into foundry goods is scalded, air effect in the steel pipe in addition, cause the steel pipe inwall to produce very thick one deck iron scale, influence in the steel pipe cooling water to the cooling effect of foundry goods itself, and after long-term the use, the iron scale blocking pipe that comes off in the pipe, the service life of reducing foundry goods.Therefore, both at home and abroad about design and manufacturing sector, for example Kawasaki, Japan system iron Co., Ltd. and Beijing Iron﹠Steel Design﹠Research Institute etc. clearly stipulate in technical conditions, must carry out pickling processes to the inwall of the steel pipe of inlaying in the foundry goods, to remove the iron oxide cortex.

At present, the method for the steel pipe inner wall oxide iron sheet layer of inlaying generally adopts the pickling processes method in the cleaning foundry goods.Because the scale structure densification, thereby pickling is difficult to clean out, and also there is fragile foundry goods itself in pickling simultaneously, and troublesome poeration is wasted man-hour, problems such as consumption fund.

The objective of the invention is to make in the foundry goods institute's steel pipe inwall of inlaying at high temperature not with air effect, cause in the steel pipe not oxidizing atmosphere, reach the steel pipe inwall and do not produce the iron oxide cortex, and then the release acid cleaning process.

The object of the present invention is achieved like this: in pouring cast part and foundry goods cooling procedure, inlay to foundry goods and to feed inert gas-nitrogen in the steel pipe, drive away the air in the steel pipe.After stopping logical nitrogen, with of the end sealing of privacy protection lid, avoid air to enter pipeline at once with the edge steel pipe.Treat to take off when foundry goods is cooled to uniform temperature the privacy protection lid.

Use method manufacturing of the present invention inside to be bumped into the foundry goods of steel pipe, for example blast furnace cooling stave etc. can be removed this procedure of pickling edge inside pipe wall oxide layer, saves time, laborsaving, province's fund, not deterioration foundry goods.

Specific embodiments of the invention are as follows:

The seamless steel pipe that earlier preparation is bumped into foundry goods is placed in the casting mold on request and fixes, and the tube head that makes its two ends all exposes outside the sandbox of casting mold, tube head one end that will be exposed at outside the sandbox by Pressure gauge and sebific duct is connected with nitrogen pipeline, connect part and tighten used nitrogen pressure 〉=0.4MPa with joint.When beginning to cast, open the nitrogen pipeline valve, in the steel pipe that is bumped into, lead to nitrogen while pouring into a mould.The nitrogen of this feeding can reclaim or emptying by the other end of tube head outside being exposed at sandbox.Pour and treat to stop after casting temperature is reduced to below 1150 ℃ logical nitrogen; at once pull out the sebific duct that connects tube head then; with of the arbitrary end sealing of privacy protection lid with the steel pipe head; in case enter air in the pipe; treat after casting temperature is reduced to below 500 ℃ the privacy protection lid to be taken off, so far finish the anti-oxidation technology of steel pipe inwall of inlaying in the foundry goods.

Claims

1, a kind of anti-oxidation method for inwall of steel pipe that is set in the foundry goods; relate in pouring cast part and foundry goods cooling procedure and in the edge steel pipe, feed nitrogen; after it is characterized in that stopping to feed nitrogen in the edge steel pipe, the end with the edge steel pipe seals with over cap at once.

2, method according to claim 1, the time that it is characterized in that adding a cover the over cap sealing should be to be lower than below 1150 ℃ when any at casting temperature.

3, method according to claim 1 and 2, the time that it is characterized in that taking off over cap should be to be lower than below 500 ℃ when any at casting temperature.